Walter...Have you physically inspected all the vacuum lines to do with the system?

There are a couple under the airbox, and one over the throttle body that break and are not usually noticed.

Yes Bill, I've checked those for flow and vacuum. They're pretty airtight.

Part of my confusion stems from the definiton I'm reading for the error code. If I understand it correctly, the system is detecting vacuum (purge) when it should not. This sounds to me like the opposite of a vacuum leak, rather, I have vacuum detected when there should be none. :?: This point is critical. If I have low/no vacuum I'm looking for one problem, if I have high/any vacuum when I should not it'* completly different.

So how the heck does this car measure vacuum? I've read about a Fuel Tank Pressure reading, but I can't find any kind of pressure transducer in my manuals. If I knew where the reading was coming from it might help my search. All I see in the system are hoses, valves, and connections, but no flow meters or pressure transducers.

Surely the MAF sensor isn't sensitive enough to detect air flow differential through a 1/4" vacuum line is it??

Or the system is "commanding" vacuum when it shouldn't be.

Before we move foreward, NO other codes, right?

Manuals are at home, and if BIll doesn't get back to you before I do, I'll post the diagnosis/service steps.

Only the P1441. It has been repeated up to 3 times on the reader (according to the guy @ autozone) but only P1441 is there. I did have it reset (erased?) twice. The first time to make sure I was getting "fresh" error codes and the second time after I replaced the solenoids (valves) to see if i fixed it. It ran about a week then reset the P1441.

I do appreciate the help.

Okay, there is a pressure transducer on top of the fuel tank. It measures a negative pressure, or vacum in the fuel tank & the EVAP system as a whole when the PCM calls for this routine to be run. It is basically a routine (commanded by the PCM) that purges the EVAP canister & checks the EVAP system integrity by toggling the purge & vent valves. That transducer may possibly be at fault, or the PCM is continuously calling for purge cycle. I'll try to do some more research in the FSM.

OK. (Gawd I hate dropping fuel tanks) It sure would be sweet to have a way to test it before replacing it. I saw a "test port" up by the canister (on the vacuum side) and I was wondering what it was for...it said to limit pressure to 1 psi regulated. I assume the purpose would be to pressurize the system and then...?

There'* already been a lengthy discussion on this topic....do a search and I am sure you'll find it.

I assume you are referring to this thread....code is different, but alot of information applies.

http://www.bonnevilleclub.com/forum/...er=asc&start=0

I'll need to review this to see the differences (if any) in the codes.

Walter, disconnect the connector at the purge valve & read pin B (with ign off) to ground with an ohmeter, it should read wide open (not grounded). Then start the engine and check to see if it changes state.

OK. I'll do it when I get back in to the house this evening.

To clarify, we're talking about the valve on the intake manifold, not the canister?

Is pin "B" marked somehow?

With power on I should be checking for voltage or continuity?